Edible microcapsule and food containing the same

ABSTRACT

An edible microcapsule comprising a core and a capsule wall, wherein the core is an edible hydrophobic substance, the capsule wall is formed by salting-out of a combination of a protein and an edible salt, and transglutaminase is used as a crosslinking agent for hardening (solidifying) the capsule wall, and a food containing the edible microcapsule.

FIELD OF THE INVENTION

[0001] The present invention relates to edible microcapsules suitablefor dried powders and foods containing the same.

BACKGROUND OF THE INVENTION

[0002] Edible microcapsules containing a hydrophobic core substance,such as fat-soluble vitamins (e.g., vitamin A, vitamin D and the like),flavor oils, and fats and oils or fatty acids (e.g., eicosapentaenoicacid (hereinafter referred to as “EPA”), docosahexaenoic acid(hereinafter referred to as “DHA”) and the like) and the like, areessentially required to be in the form of dried powder from thestandpoint of preservation stability.

[0003] The state-of-the-art microcapsules having a small particle sizeof not larger than 100 μm are obtained by spray drying with a spray dryapparatus. This method has been utilized, in general, for granulating aliquid composition into fine particles. When microcapsules are preparedaccording to this method, a dispersing solution in which a hydrophobiccore substance, such as a flavor oil, a fatty acid or the like, isemulsified in an aqueous solution of a coating substance, such as gumarabic, dextrin or the like, is prepared, and the obtained dispersingsolution is spray-dried in a high-temperature air stream to obtainpowder particles of microcapsules. This method is characterized in thatthe dispersing solution is made into fine droplets having a large totalsurface area by spray drying into a high-temperature air stream, therebyassuring an increased drying effect. Accordingly, the method is rathersuitable to prepare powder particles having a particle size of notlarger than 100 μm, preferably the order of several tens of microns.

[0004] For preparing large particles having a particle size of notsmaller than 1,000 μm, on the other hand, a so-called orifice methodusing a double orifice (with a structure providing an inner orificewithin an outer orifice of relatively larger calibre) has been put topractical use, in which a liquefied capsule wall-forming substance arefed under pressure into the outer orifice and then extruded therefromhugging its calibre, wraps around a droplet of the core substance aredripped out of a nozzle at the outlet of the inner orifice, and the thuswrapped up droplets are dropped into an oil bath for cooling andhardening (solidifying) the capsule wall, and the thus mademicrocapsules are collected from the oil and further dried.

[0005] Apart from the above-described two methods that have been inpractical use, coacervation has been attracting attention as a techniquefor obtaining edible microcapsules having a particle size of about 100to 400 μm, which size is the most suitable for addition to foods.Coacervation is divided into two methods, i.e., complex coacervation andsimple coacervation. Salting-out is included in simple coacervation.Complex coacervation consists in coacervation (phase separation) inducedby the electrolytical action between polycations and polyanions, whichcauses separation of a polymer rich phase out of the equilibrium liquidwith subsequent precipitation and adsorption around surface of thedroplets of a hydrophobic core substance to form a capsule wall.Examples of edible combinations of polycations and polyanions includegelatin-gum Arabic, gelatin-CMC Na, and gelatin carrageenan.

[0006] The outline of encapsulation by complex coacervation is asfollows.

[0007] All of the following processes are carried out under continuousagitation.

[0008] 1) A hydrophobic core substance is emulsified or dispersed in apositively charged water-soluble polymer solution having the propertiesof a protective colloid.

[0009] 2) An oppositely charged hydrophilic colloid solution is addedthereto.

[0010] 3) The colloid concentration, pH, temperature and the like of thesystem are controlled so as to induce coacervation (phase separation),thereby to precipitate a colloid rich phase of the water-soluble polymeronto the surface of the hydrophobic core substance to form amicrocapsule wall.

[0011] 4) The capsule wall of the resulting microcapsules isinsolublized and stabilized by crosslinking.

[0012] In the step of insblublizing the capsule wall, aldehydes, such asformaldehyde, glutaraldehyde and the like, are generally used as acrosslinking agent for hardening (in the present invention, oftenreferred to as a “crosslinking insolublizing agent”); however, they arenot suitable for foods. Tannic acid, gallic acid and the like are knownas a crosslinking agent for hardening applicable to foods; however, thecrosslinking effect thereof is not sufficient. Moreover, somecrosslinking agents for hardening usable for foods give their odor ortaste to the capsule wall made of, e.g., gelatin.

[0013] Under these circumstances, the crosslinking treatment forhardening or solidifying (in the present invention, often referred to as“crosslinking insolublizing treatment”) using transglutaminase, which isan enzyme disclosed in JP-A-1-27471, is remarkably superior to theabove-described conventional crosslinking treatment for hardening orsolidifying (the term “JP-A” as used herein means an “unexaminedpublished Japanese patent application”). Application of transglutaminaseas a crosslinking agent for hardening or solidifying of a capsule wallto edible microcapsules obtained by coacervation has been alreadyreported (see JP-A-5-292899).

[0014] Spray drying using a spray dry apparatus is a very old techniquethat has been in large practical use. It has been utilized in powderingskim milk since the early twentieth century (Nihon Funtai Kogyo GijyutuKyokai (ed.), Granulating Handbook).

[0015] With the broadening of application, the spray dry apparatus hasincreased in speed and automation, and the technique has been in wideuse as a means for finely granulating a liquid substance.

[0016] Spray drying has the following characteristics: (1) powderparticles can be obtained directly from a liquid substance; (2) a liquidsubstance is made into fine droplets having a large surface area by thejet of a liquid substance from a pressure nozzle or the centrifugalforce of a high-speed rotary disc, thereby to increase the dryingefficiency; and (3) spray drying is suitable for continuous massproduction. Therefore, spray drying is a very reasonable technique forfinely granulating a liquid substance.

[0017] However, dry-powdered products obtained by spray drying comprisemany hollow spherical particles. As is understood from the attributes ofthe process, it is difficult to obtain dried powder particles ofmicrocapsules in which individual particles of a core substance arecompletely enveloped (encapsulated) with a continuous wall even if asuspension in which the core substance is emulsified in theencapsulating material solution is dry-granulated. Furthermore, if thecapsule wall obtained by spray drying is required to have someprotecting properties, the wall material should be used in a proportionof 70 to 80% based on the microcapsules, which means that the amount ofthe core substance is very small.

[0018] In the orifice method using a double orifice (with a structureproviding an inner orifice within an outer orifice of relatively largercalibre), a microcapsule is obtained in such that a liquid wall formingsubstance, such as gelatin and the like, is extruded from the outerorifice, wraps around a droplet of the liquid core substance are drippedfrom nozzle of the inner orifice, and the wrapped up particles aredipped into an oil bath for cooling and solidifying the wall formingsubstance. The microcapsules obtained by this method with a subsequentprocess for drying are far more satisfactory than those obtained byspray drying in that the core substance is completely wrapped up with acontinuous wall.

[0019] However, because the orifice method requires a mechanical processof feeding, extruding and dripping a liquid core substance and a liquidcapsule wall substance as well to an extremely narrow calibre of theorifices with a high pressure pump, it is very difficult to obtain fineparticles having a particle size of not larger than 1,000 μm and havinga thin capsule wall. Mass production by the orifice method can beachieved only by increasing the number of double orifice and increasingthe speed of such mechanical operations as feeding, extruding anddripping with a fine control of eventual size of a droplet come out ofthe orifice. This requires expensive equipment for increasing the pumppressure, and automated steps to optimize amount of the core substanceand the capsule wall substance to be fed, extruded and dripped and forsubsequent cooling, drying, recovering and defatting, and integratingsubtle control into the automated steps.

[0020] The complex coacervation for obtaining powder particles of ediblemicrocapsules having a particle size of 100 to 400 μm, which size givesno discomfort in the mouth, has previously been proposed inJP-A-5-292899. According to the disclosed method, the final step ofdrying a microcapsule slurry prepared by complex coacervation is carriedout by spray drying with a spray dry apparatus for simultaneouslyremoving water and drying in the case of obtaining edible microcapsuleshaving a small particle size of not larger than 100 μm.

[0021] Also, for preparation of edible microcapsules having a mediumparticle size of not smaller than 100 μm, the step of drying by afluidized bed method or blowing of warm or hot air is carried out afterremoving water of the microcapsule slurry through filtrations to obtainfilter cake and dusting them with fine particle of starch powder toprevent the primary microcapsule particles from being agglomerated whiledrying.

[0022] Since the capsule wall of the microcapsules prepared by complexcoacervation are highly swollen with water (having a high watercontent), the efficiency of dehydration before drying treatment is poor.Besides, the surface of the capsule wall is so sticky that a largequantity of an antiblock agent is required, but yet microcapsules in theprimary particle state are hardly obtained, showing tendency toagglomeration, and the resulting product has a reduced content of thecore substance.

SUMMARY OF THE INVENTION

[0023] An object of the present invention is to provide ediblemicrocapsules which (1) have a capsule wall having a small degree ofswelling (low water content), (2) are suited to dried powder because ofits low stickiness being negligible, and (3) have a reduced capsule wallthickness to ensure a high content of the core substance.

[0024] Another object of the present invention is to provide foodscontaining the edible microcapsules.

[0025] These and other objects of the present invention have beenattained by an edible microcapsule comprising a core and a capsule wall,wherein said core is an edible hydrophobic substance; said capsule wallis formed by salting-out of a combination of a protein and an ediblesalt; and transglutaminase is used as a crosslinking agent for hardening(solidifying) said capsule wall.

[0026] Furthermore, these and other objects of the present inventionhave been attained by a food comprising the above-described ediblemicrocapsule.

[0027] Moreover, these and other objects of the present invention havebeen attained by a method for preparing the above-described ediblemicrocapsule.

DETAILED DESCRIPTION OF THE INVENTION

[0028] Salting-out is one of simple coacervation techniques as describedabove. It is characterized by using a salt, such as sodium phosphate orthe like, in place of the polyanion, e.g., gum arabic, CMC Na or thelike, as used in complex coacervation.

[0029] Because the capsule wall of the edible microcapsules formed bysalting-out according to the present invention has a low water contentand a low degree of swelling and is therefore little sticky, themicrocapsules are easily dried to provide powder of primary particles ina good yield.

[0030] By the use of a neutral to weakly alkaline salt, the system aftercapsule wall formation has a pH in the vicinity of neutrality, which isadvantageous for transglutaminase to act as a crosslinking agent forhardening (solidifying) the capsule wall. As a result, a sufficientcrosslinking effect is produced to provide a strong capsule wallaffording improved protection for the core substance. The ediblemicrocapsules of the present invention is characterized by achievementsin both reduction of capsule wall thickness and increase in the highestpossible content of the core substance.

[0031] In the edible microcapsules of the present invention, the ediblehydrophobic substance is used as a core substance, the capsule wall isformed by salting-out of a combination a protein with an edible salt,and transglutaminase is used as a crosslinking agent for hardening thecapsule wall. Examples of the protein for use in the present inventioninclude a variety of edible proteins, such as gelatin, casein, soybeanprotein, corn protein, and collagen. Among these, gelatin is the mostsuitable for its ease of use and the highest capability ofencapsulation.

[0032] Examples of the edible salt for use in the present inventioninclude sodium chloride, sodium acetate, sodium nitrate, sodiumcarbonate, sodium sulfite, sodium lactate, sodium citrate, sodiumsulfate, various sodium phosphates (e.g., sodium metaphosphate, sodiummonohydrogenphosphate, sodium dihydrogenphosphate and the like),ammonium chloride, ammonium sulfate, potassium carbonate, calciumchloride, magnesium sulfate, iron sulfate, and zinc sulfate, andmixtures of two or more thereof. From the standpoint of ease of use andcapability of encapsulation, preferred of them are sodium acetate,sodium sulfite, sodium sulfate, sodium metaphosphate, sodiummonohydrogenphosphate, sodium dihydrogenphosphate, ammonium chloride,and ammonium sulfate, and mixtures of two or more thereof.

[0033] Transglutaminase is an enzyme catalyzing acyl transfer reactionbetween the γ-carboxyamide group of glutamine in peptide chains.Transglutaminase forms an intramolecular or intermolecular crosslinkedstructure ε-(γ-Glu)-Lys upon action of a lysine residue of proteins asan acyl receptor.

[0034] Transglutaminase includes calcium-independent one andcalcium-dependent one, both of which can be used in the presentinvention. The former includes those of microorganism origin (seeJP-A-64-27471), and the latter includes those of guinea pig liver origin(see JP-B-1-50382, the term “JP-B” as used herein means an “examinedJapanese patent publication”), those of fish origin (see Nobuo Seki,Nihon Suisan Gakkaishi, Vol. 56, pp. 125-132 (1990)), factor XIII inblood and the like. Additionally, transglutaminase obtained by geneticrecombination is also useful (see JP-A-1-300889, JP-A-5-199883 and thelike). Although transglutaminase for use in the present invention is notlimited in origin and process of preparation, the calcium-independentone that does not require calcium for expression of its activity ispreferred.

[0035] The edible hydrophobic substance as a core substance is notparticularly limited and includes vegetable oils, such as corn oil,soybean oil, rape seed oil, peanut oil, palm oil and the like; animaloils, such as fish oil, lard, beef tallow and the like; fatty acids,such as α-linolenic acid, EPA, DHA and the like; flavor oils; andfat-soluble vitamins and the like. Edible waxes may also be used. Thesecore substances are selected appropriately and can be used eitherindividually or as a combination of two or more thereof according to thepurpose. If desired, the core substance may contain seasonings, spices,emulsifying agents, coloring agents, and the like.

[0036] The flavor oils include meat flavors, fish and shell flavors suchas dried bonito flavor and the like, fruit flavors, and vegetableflavors. The fat-soluble vitamins include vitamin A, vitamin D, vitaminE, vitamin F, vitamin K and the like vitamins. These flavors andvitamins may be used either individually or as a combination thereof.

[0037] The amount of the edible hydrophobic substance used is notparticularly limited and is usually about 1 to 10 g per g of a capsulewall-forming protein, such as gelatin and the like.

[0038] The above-described hydrophobic core substances may be used incombination with water-soluble substances, such as proteins, aminoacids, nucleic acids, enzymes and the like.

[0039] Salting-out method for preparing microcapsules, which is one ofsimple coacervation techniques, can be carried out as follows.

[0040] The ratio of the edible hydrophobic substance, protein, water andthe like to be subjected to salting-out is not limited as far as iswithin the range commonly used in salting-out. A general procedure ofsalting-out method is described below for an illustrative purpose butnot for limitation.

[0041] A 1 to 20 wt % aqueous solution of a protein (e.g., gelatin) isprepared, and 1 to 200 ml or 1 to 200 g of an edible hydrophobicsubstance is added thereto per 100 g of the foregoing aqueous solutionand dispersed to form droplets having a particle size of about 100 to400 μm to prepare an O/W emulsion. To the O/W emulsion was added 10 to200 g, per 100 g of the emulsion, of distilled water of 30 to 70° C.,while maintaining the temperature of the emulsion at 30 to 70° C.

[0042] A 0.5 to 30 wt % aqueous solution of an edible salt is addeddropwise to the emulsion in a total amount of 10 to 200 g per 100 g ofthe emulsion to form a coating film (capsule wall) enveloping the ediblehydrophobic substance. The system is slowly cooled to 10 to 40° C. tothicken the capsule wall. Then transglutaminase, a crosslinking agentfor hardening (solidifying) the capsule wall, is added to the system.While not limiting, the enzyme reaction is usually carried out at 10 to60° C. for 10 minutes to 48 hours. Transglutaminase is added in anamount of 0.1 to 100 units per gram of the protein (e.g., gelatin)present in the system.

[0043] In the process of hardening (solidifying) of a capsule wall bytransglutaminase, methyl cellulose, carboxymethyl cellulose and the likemay be added to the system in order to prevent agglomeration or cakingof capsule particles. Also, in the process of encapsulation through thesalting out step, substances other than the edible hydrophobicsubstance, protein, and edible salt may of course be added.

[0044] The resulting edible microcapsules are then dried either as is oras mixed with an antiblock agent (drying additive), such as cellulosefine powder, starch powder and the like. Drying can be carried out byany of general drying means, such as warm air drying, hot air drying,freeze drying, vacuum drying, fluidized bed drying such and the like.

[0045] The edible microcapsules according to the present invention canbe added to a wide variety of foods, such as soup, chewing gum,pouch-packed foods and the like. That is, the food according to thepresent invention comprises the edible microcapsules, optionally alsoincluding an acceptable carrier or diluent. Foods containing the ediblemicrocapsules of the present invention are excellent in flavor andtaste.

[0046] The present invention will now be illustrated in greater detailby way of Examples, but it should be understood that the invention isnot construed as being limited thereto. Unless otherwise indicated, allpercents are by weight.

EXAMPLE 1

[0047] To 40 g of a 10% aqueous solution of gelatin (produced by NippiCo., Ltd.) was added 60 ml (equivalent to about 54 g) of flavor (OrangeFlavor, produced by Takasago International Corporation) and dispersed toprepare an O/W emulsion having a dispersed particle size of 200 μm. Theemulsion was kept at 50° C., and 40 g of distilled water at 50° C. wasadded thereto. Thirty grams of a 20% aqueous solution of sodiumcarbonate were added to the emulsion, and 10 g thereof was furtherslowly added thereto dropwise thereby to form a gelatin film envelopingthe flavor oil droplet by salting-out.

[0048] The system was gradually cooled to 30° C. to thicken the gelatinfilm, and 2 g of a transglutaminase preparation (ACTIVA® TG-S, producedby Ajinomoto Co., Inc.; containing 200 units of transglutaminase, i.e.,40 units of transglutaminase per gram of gelatin) was added theretowhile keeping the system at 30° C., followed by stirring at thattemperature for 2 hours and then at 40° C. overnight. The stirring wasstopped, and the microcapsules were collected and dehydrated byfiltration under reduced pressure by using qualitative filter paper No.1 (produced by Toyo Roshi Co., Ltd.).

[0049] Twenty grams of crystalline cellulose fine powder which was anantiblock agent (Avicel, produced by Asahi Chemical Industry Co., Ltd.)were lightly mixed with the filter cake, and the mixture was spread overa tray and air-dried at 40° C. The resulting powder was passed through a140 mesh screen to remove the antiblock agent as completely as possibleto obtain 66 g of single-cored capsules as slightly yellowish powder.The flavor oil content of the microcapsule powder was about 70%, whichcorresponded to 96% of the charged flavor oil.

EXAMPLE 2

[0050] In 60 g of a 10% aqueous solution of gelatin (produced by NippiCo., Ltd.) was dispersed 40 g of DHA oil (produced by Nihon Kagaku SiryoCo., Ltd.) to prepare an O/W emulsion having a dispersed particle sizeof 400 μm. The emulsion was kept at 50° C., and 70 g of distilled waterat 50° C. was added thereto. Sixty grams of a 1.0% aqueous solution ofsodium metaphosphate were added dropwise to the emulsion, followed bygradually cooling to 30° C. to form a thick gelatin wall around the oildroplet by salting-out.

[0051] The system was kept at 30° C., and 4 g of a transglutaminasepreparation (ACTIVA®TG-B, produced by Ajinomoto Co., Inc.; containing240 units of transglutaminase, i.e., 40 units of transglutaminase pergram of gelatin) was added thereto, followed by stirring at thattemperature for 24 hours. The microcapsules thus formed were collectedon a 100 mesh net, washed with water, and dehydrated by filtration underreduced pressure using the above-described qualitative filter paperNo. 1. Thirty grams of starch powder were lightly mixed with the filtercake, and the mixture was spread over a tray and air-dried at roomtemperature. The resulting powder was passed through a 120 mesh screento remove excess starch powder as completely as possible to obtain 69 gof single-cored capsules as white powder.

EXAMPLE 3

[0052] Microcapsules according to the present invention (sample 1) andcomparative microcapsules prepared by conventional complex coacervation(sample 2) were compared in terms of (1) the volume of the coacervate,i.e., the gelatin-rich droplets and (2) the solid content of theequilibrium aqueous solution containing the non-coacervatedgelatin-starved phase after coacervation. Preparation of Sample 2 (forcomparison): 10% Gelatin aqueous solution 60 g Distilled water 230 g 10% Gum arabic aqueous solution 60 g

[0053] A microcapsule suspension was prepared from the above componentswhile controlling the stirring speed, pH and cooling rate so as toobtain coacervate droplets having a particle size of about 100 μm. Fourgrams of a transglutaminase preparation ACTIVA®TG-B were added to thesystem, followed by stirring at 30° C. for 24 hours. Preparation ofSample 1: 10% Gelatin aqueous solution 60 g Distilled water 70 g 1%Sodium phosphate aqueous solution 60 g

[0054] A microcapsule suspension was prepared from the above componentsin the same manner as for sample 2. To the system was added 155 g ofdistilled water so as to give the same water content as that of sample2, and stirring was continued for an additional period of 3 hours.

[0055] Method of Measurement:

[0056] Each sample was put in a 500 ml measuring cylinder and allowed tostand for 24 hours to precipitate the coacervate, i.e, gelatin-richdroplets. The volume of the precipitated gelatin particles and thesolids content of the equilibrium aqueous solution containing thenon-coacervated gelatin-starved phase after coacervation were measured.The results obtained are shown in Table 1 below. TABLE 1 Sample 1 Sample2 (Invention) (Comparison) Volume of gelatin 134.0 ml 166.3 ml particlesSolids content of 0.406% 0.552% equilibrium solution

[0057] After the measurement, the coacervate of sample 1 having aparticle size of 100 μm could be easily re-dispersed by stirring with astirrer, whereas the coacervate of sample 2 was difficult todisaggregate on stirring.

[0058] Judging from the fact that samples 1 and 2 had substantially thesame solids content in the equilibrium solution, it is seen that thegelatin charged had undergone standard phase separation and precipitatedas gel. Since the obtained gelatin particles of the two samples wereadjusted to have the same size, the gelatin particles were to have thesame volume if the gelatin concentrations were the same. In fact, thevolume of the gelatin particles of sample 1 was noticeably smaller thanthat of sample 2, which means the gelatin particles of sample 1 had ahigher concentration.

[0059] The easy re-dispersibility of the precipitated gelatin particlesof sample 1 proves that the surface of the gelatin particles of sample 1is less sticky.

[0060] It was thus verified that the edible microcapsules according tothe present invention are remarkably advantageous in drying to powderover the microcapsules formed by complex coacervation.

EXAMPLE 4

[0061] Edible microcapsules were prepared in the same manner as inExample 2, except for replacing 40 g of DHA oil with 40 g of sesame oil.

[0062] The sesame oil microcapsules were packed in a retortable pouchtogether with “tofu” cooked with mince and seasonings (a Chinese food)and retorted. After 3 months preservation, the pouch was opened, and thefood was found still keeping a flavor of sesame.

[0063] As described above, the edible microcapsules according to thepresent invention have a low water content and a low degree of swellingin the capsule wall thereof and are therefore little sticky to eachother. The microcapsules can be dried to single-cored microcapsulepowder in a good yield and are therefore suited for preparation of driedpowder of edible microcapsules. The thickness of the capsule wall iscontrollable with improved freedom, which eventually affords improvedfreedom in deciding the rate of release of the core substance.

[0064] While the invention has been described in detail and withreference to specific examples thereof, it will be apparent to oneskilled in the art that various changes and modifications can be madetherein without departing from the spirit and scope thereof.

[0065] This application is based on application Nos. Hei 8-850 and8-332315 filed in Japan, the content of which is incorporated hereintoby reference.

What is claimed is:
 1. An edible microcapsule comprising a core and acapsule wall, wherein said core is an edible hydrophobic substance; saidcapsule wall is formed by salting-out of a combination of a protein andan edible salt; and transglutaminase is used as a crosslinking agent forhardening said capsule wall.
 2. The edible microcapsules as claimed inclaim 1, wherein said protein is gelatin.
 3. The edible microcapsules asclaimed in claim 1, wherein said edible salt is selected from the groupcomprising sodium acetate, sodium sulfite, sodium sulfate, sodiummetaphosphate, sodium monohydrogenphosphate, sodium dihydrogenphosphate,ammonium chloride, ammonium sulfate, and a mixture of two or morethereof.
 4. A food comprising an edible microcapsule comprising a coreand a capsule wall, wherein said core is an edible hydrophobicsubstance; said capsule wall is formed by salting-out of a combinationof a protein and an edible salt; and transglutaminase is used as acrosslinking agent for hardening said capsule wall.
 5. The food asclaimed in claim 4, wherein said protein is gelatin.
 6. The food asclaimed in claim 4, wherein said edible salt is selected from the groupcomprising sodium acetate, sodium sulfite, sodium sulfate, sodiummetaphosphate, sodium monohydrogenphosphate, sodium dihydrogenphosphate,ammonium chloride, ammonium sulfate, and a mixture of two or morethereof.
 7. A method for preparing an edible microcapsule, whichcomprises the following steps: forming a capsule wall on a core bysalting-out of a combination of a protein and an edible salt; andhardening said capsule wall with a crosslinking agent, wherein said coreis an edible hydrophobic substance; and said crosslinking agent istransglutaminase.
 8. The method as claimed in claim 7, wherein saidprotein is gelatin.
 9. The method as claimed in claim 7, wherein saidedible salt is selected from the group comprising sodium acetate, sodiumsulfite, sodium sulfate, sodium metaphosphate, sodiummonohydrogenphosphate, sodium dihydrogenphosphate, ammonium chloride,ammonium sulfate, and a mixture of two or more thereof.